Trecho da obra "WHAT IS CALLED THINKING?", de Martin Heidegger.
"We come to know what it means to think when we ourselves try to think. If the attempt is to be successful, we must be ready to learn thinking. As soon as we allow ourselves to become involved in such learning, we have admitted that we are not yet capable of thinking.
Yet man is called the being who can think, and rightly so. Man is the rational animal. Reason, ratio, evolves in thinking. Being the rational animal, man must be capable of thinking if he really wants to. Still, it may be that man wants to think, but can’t. Perhaps he wants too much when he wants to think, and so can do too little. Man can think in the sense that he possesses the possibility to do so. This possibility alone, however, is no guarantee to us that we are capable of thinking. For we are capable of doing only what we are inclined to do. And again, we truly incline only toward something that in turn inclines toward us, toward our essential being, by appealing to our essential being as the keeper who holds us in our essential being. What keeps us in our essential nature holds us only so long, however, as we for our part keep holding on to what holds us. And we keep holding on to it by not letting it out of our memory. Memory is the gathering of thought. Thought of what?